Drifter Sizing
Helmet Size	Head Cir. (IN)	Head Cir. (CM)	Hat Size
XS	20-1/2 - 20-7/8	52 - 53	6-1/2 - 6-5/8
SM	21-1/4 - 21-5/8	54 - 55	6-3/4 - 6-7/8
MD	22 - 22-3/8	56 -57	7 - 7-1/8
LG	22-3/4 - 23-1/4	58 - 59	7-1/4 - 7-3/8
XL	23-5/8 - 24	60 -61	7-1/2 - 7-5/8
XXL	24-3/8 - 24-3/4	62 - 63	7-3/4 - 7-7/8